Recent epidemiological and clinical investigations have indicated a significant correlation between dietary supplements of polyunsaturated fatty acids (PUFA), especially omega-3 PUFA's, and reduced incidence of coronary heart disease. Clinical interests have focused on potential usage of omega-3 PUFA's in the treatment of hypercholesteremia and hypertriglyceridemia. At present the only source of omega-3 PUFA's is oil expressed from certain marine fishes. However, many species of algae also produce large amounts of omega-3 PUFA's and we believe that this group of organisms could provide an invaluable supply source of omega-3 PUFA's for clinical trials and/or food additive testing using algal monoculture. Determination of the technological feasibility (Phase I) of this strategy will involve the following near term objectives: - Establish in several omega-3 PUFA producing algal species in culture. - Optimize the growth conditions and determine the maximum omega-3 PUFA productivities. - Extract and purify the omega-3 PUFA's in preparative quantities. If significant advantages over the fish oil source are identified, the Phase II effort will involve scale-up production and an effort targeted to increase the specific omega-3 PUFA outputs from our algal sources by strain improvement and genetic modification.